The Labour party in Wales has endorsed plans to form a coalition government with Plaid Cymru in the Welsh assembly.
Support for the controversial political deal comes despite opposition from senior Labour figures, including former party leader Lord Kinnock, and several Labour MPs and Welsh assembly members.
At a special conference in Cardiff, various party groups, trade unions and affiliated organisations voted by 78.43 per cent to 21.57 per cent to support the proposed coalition.
Plaid Cymru is now set to enter government for the first time next week, with supporters of the nationalist party also expected to back the deal with Labour during a separate conference today.
The political partnership between the two parties, who have at times in the past been bitterly opposed on various issues, will also see both sides campaign to gain public support in Wales over plans to transform the region's assembly into a Scottish-style parliament.
Under the One Wales document negotiated between Labour and Plaid Cymru the parties agreed to hold a referendum on whether the Welsh assembly should be granted full law-making powers.
Over 95 per cent of trade unions and groups affiliated to the Welsh Labour party voted in favour of a coalition Plaid Cymru, while constituency parties and other party bodies voted by a majority of 61 per cent to back the deal.
Welcoming the result Welsh Labour leader Rhodri Morgan said he was pleased that both wings of his party had chosen to support the agreement with Plaid Cymru, forged after his party failed to secure a majority at May's assembly elections.
"This gives us a very good indication that the party will unite behind this overwhelming vote," he said.
However Mr Morgan, whose political future had somewhat rested on the result of the vote, stressed that a referendum on giving the Welsh assembly law-making powers would not be held until the parties had "tested the waters of public opinion".
Amid opposition to the planned coalition from some senior Labour figures, Welsh secretary Peter Hain insisted that yesterday's result was "not a vote for nationalism".
But Nick Bourne, leader of the Conservative party in the Welsh assembly, said it showed there was still "significant opposition" within Labour ranks to the plan to join up with Plaid Cymru.
"Tonight's vote and the events of the last few weeks suggest that Rhodri Morgan could find it easier to deal with his potential coalition partners than many members of his own party," he said, commenting yesterday.
"This vote could well sew the seeds of conflict within Welsh Labour," Mr Bourne added.